Patent GB-467492-A (GB)
Title: Condensation products of methacrylamide and formaldehyde
IPC: C08F20/56
Filed: 1935-11-11
Abstract: Methacrylamide, mixtures thereof with one or more acrylic or vinyl compounds, or corresponding polymers, are condensed with formaldehyde, which may be in aqueous or other solution, as vapour, or as paraformaldehyde.  Polymerization and condensation may take place simultaneously.  The acrylic or vinyl compounds include vinyl chloride or acetate; styrene; acrylic nitrile; methyl, ethyl, butyl or amyl acrylate; or methacrylic compounds. There may be incorporated one or more polyhydric alcohols, e.g. glycol, glycerol; metal salts, e.g. aluminium formate, acetate or sulphate, or zinc chloride; softening agents, e.g. acetins, phthalic esters, adipic esters drying and non-drying oils, fats, waxes, and fatty acids; cellulose compounds, e.g. ethers and esters; natural and artificial resins, e.g. urea-, phenol-, and p-toluenesulphonamidealdehyde resins; rubber, e.g. latex; gelatine, glue, or starch.  The products may be used as glass substitutes and interlayers for safety glass; moulded, cut, or turned articles; lacquers; textile assistants; thickening agents, e.g. for dyes; protective colloids for latex; gelatine substitutes, e.g. for photographic or printing purposes; electrical insulation and cable casings; adhesives; gas-impermeable fabrics, e.g. for gas-masks; medical purposes, e.g. palates, plaster; artificial leather, artificial silk; gramophone records.  Films of the products may be used alone, e.g. for membranes and tubes; be applied to other films, especially those non-permeable to water, e.g. of cellulose ester, especially celluloid, of polyvinyl esters, polystyrene, polyacrylic or polymethacrylic esters, of interpolymers and mixtures of polymers; or be used as intermediate layers coated with other materials, e.g. polyacrylic ester, and may contain a solvent for the coatings.  In examples: (1) an aqueous solution of polymethacrylamide, glycerine, formaldehyde, boric acid, and aluminium formate is heated, then poured on to a glass plate to produce films or slabs; (2) methacrylamide is heated with paraformaldehyde in toluene solution; (3), (4), a film is prepared by evaporating an aqueous solution of polymethacrylamide and glycerine, and is (3) immersed in aqueous formaldehyde, (4) suspended in formaldehyde vapour; (5) aqueous formaldehyde and methacrylamide solutions are heated together; (6) methacrylamide is polymerized in aqueous solution in the presence of hydrogen peroxide, and treated with aqueous formaldehyde; (7) methacrylamide and butyl acrylate are polymerized in ethyl, propyl or butyl alcohol solution in the presence of benzoyl peroxide, and the polymer treated with paraformaldehyde, (instead of an alcohol, there may be used a ketone, e.g. acetone, methyl ethyl ketone); (8) a film of the polymer of example 7 treated with paraformaldehyde gave an alcohol-soluble film, insolubilized by treatment with aqueous formaldehyde.  Specification 467,402 is referred to.  According to the Provisional Specification interpolymers may be prepared with polymerizable, unsaturated organic compounds in general; and there may be added to the products polyvinyl alcohol, polyacrylic and polymethacrylic acids and esters.ALSO:Protective colloids for latex may be prepared from methacrylamide, mixtures thereof with one or more acrylic or vinyl compounds, or corresponding polymers by condensation with formaldehyde, which may be in aqueous or other solution, as vapour, or as parafommaldehyde.  Specification 467,402, is referred to.